Travis: Added BioNetGen to dependencies
Travis: Added BioNetGen to dependencies

neurord/pysb,LoLab-VU/pysb,alubbock/pysb,pysb/pysb,neurord/pysb,johnbachman/pysb,neurord/pysb,jmuhlich/pysb,LoLab-VU/pysb,johnbachman/pysb